ios - encoding:NSISOLatin1StringEncoding with .xml file -

why can't save str in .xml file?

nsstring *strdata = @"issam  bey"; nsmutabledata *objnsdata = [nsmutabledata datawithdata:[strdata datausingencoding:nsisolatin1stringencoding]];   objnsdata = [objnsdata encryptaes:@"12345678901234561234567890123456"];  nsstring *str=[[nsstring alloc] initwithdata: objnsdata encoding:nsisolatin1stringencoding];